In USE OF FRESNEL ZONE PLATES FOR MATERIAL PROCESSING, filed Jan. 3, 1994, Ser. No. 08/177,356, a Continuation-in-Part of Ser. No. 07/940,008 filed Sep. 3, 1992, now U.S. Pat. No. 5,362,940 which was a File Wrapper Continuation of Ser. No. 07/612,212 filed Nov. 9, 1990, now abandoned and assigned to the common assignee herein, the scanning of computer generated holograms utilizing a scanning beam of coherent light for the direct processing of a substrate--such as a polyimide layer--is disclosed. In this application, these processing techniques are improved upon and generalized for greater efficiency and effectiveness in processing.
Flex circuits are mechanically flexible electrical circuits. Such flex circuits find use in modern automobiles, computers, cameras, and other locations where flexible substrates make the required electrical connections in circuits. The working features required to be placed on the substrates for such flex circuits are not dense. Specifically, the features are relatively far apart.
Heretofore, such substrates have been manufactured without direct processing with light. Multi-step chemical processes have been utilized.
Direct laser ablation in the process steps of manufacture of such flex circuits has not been used to great advantage. First, large areas of the substrates are required to be processed. In most computer generated holograms (CGHs) the area of possible scan on the computer generated hologram is much smaller than the area which must be processed on such large substrates. Because of the disparate size difference between the area than can be optically scanned and the substrate that must be scanned, such direct processing has not been utilized.